Donald L Weaver

University of Vermont, Burlington, Vermont, United States

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Publications (124)929 Total impact

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    ABSTRACT: Background: Primary care providers and health systems have prominent roles in guiding effective cancer screening. Objective: To characterize variation in screening abnormality rates and timely initial follow-up for common cancer screening tests. Design: Population-based cohort undergoing screening in 2011, 2012, or 2013 at seven research centers comprising the National Cancer Institute-sponsored Population-based Research Optimizing Screening through Personalized Regimens (PROSPR) consortium. Participants: Adults undergoing mammography with or without digital breast tomosynthesis (n = 97,683 ages 40-75 years), fecal occult blood or fecal immunochemical tests (n = 759,553 ages 50-75 years), or Papanicolaou with or without human papillomavirus tests (n = 167,330 ages 21-65 years). Intervention: Breast, colorectal, or cervical cancer screening. Main measures: Abnormality rates per 1000 screens; percentage with timely initial follow-up (within 90 days, except 9-month window for BI-RADS 3). Primary care clinic-level variation in percentage with screening abnormality and percentage with timely initial follow-up. Key results: There were 10,248/97,683 (104.9 per 1000) abnormal breast cancer screens, 35,847/759,553 (47.2 per 1000) FOBT/FIT-positive colorectal cancer screens, and 13,266/167,330 (79.3 per 1000) abnormal cervical cancer screens. The percentage with timely follow-up was 93.2 to 96.7 % for breast centers, 46.8 to 68.7 % for colorectal centers, and 46.6 % for the cervical cancer screening center (low-grade squamous intraepithelial lesions or higher). The primary care clinic variation (25th to 75th percentile) was smaller for the percentage with an abnormal screen (breast, 8.5-10.3 %; colorectal, 3.0-4.8 %; cervical, 6.3-9.9 %) than for the percentage with follow-up within 90 days (breast, 90.2-95.8 %; colorectal, 43.4-52.0 %; cervical, 29.6-61.4 %). Conclusions: Variation in both the rate of screening abnormalities and their initial follow-up was evident across organ sites and primary care clinics. This highlights an opportunity for improving the delivery of cancer screening through focused study of patient, provider, clinic, and health system characteristics associated with timely follow-up of screening abnormalities.
    No preview · Article · Dec 2015 · Journal of General Internal Medicine
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    ABSTRACT: Elevated mammographic density (MD) is an established breast cancer risk factor. Reduced involution of terminal duct lobular units (TDLUs), the histologic source of most breast cancers, has been associated with higher MD and breast cancer risk. We investigated relationships of TDLU involution with area and volumetric MD, measured throughout the breast and surrounding biopsy targets (peri-lesional). Three measures inversely related to TDLU involution (TDLU count/mm2, median TDLU span, median acini count/TDLU) assessed in benign diagnostic biopsies from 348 women, ages 40-65, were related to MD area (quantified with thresholding software) and volume (assessed with a density phantom) by analysis of covariance, stratified by menopausal status and adjusted for confounders. Among premenopausal women, TDLU count was directly associated with percent peri-lesional MD (P-trend=0.03), but not with absolute dense area/volume. Greater TDLU span was associated with elevated percent dense area/volume (P-trend<0.05) and absolute peri-lesional MD (P=0.003). Acini count was directly associated with absolute peri-lesional MD (P=0.02). Greater TDLU involution (all metrics) was associated with increased nondense area/volume (P-trend≤0.04). Among postmenopausal women, TDLU measures were not significantly associated with MD. Among premenopausal women, reduced TDLU involution was associated with higher area and volumetric MD, particularly in peri-lesional parenchyma. Data indicating that TDLU involution and MD are correlated markers of breast cancer risk suggest that associations of MD with breast cancer may partly reflect amounts of at-risk epithelium. If confirmed, these results could suggest a prevention paradigm based on enhancing TDLU involution and monitoring efficacy by assessing MD reduction.
    No preview · Article · Dec 2015 · Cancer Prevention Research
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    ABSTRACT: Objectives: "Assurance behaviors" in medical practice involve providing additional services of marginal or no medical value to avoid adverse outcomes, deter patients from filing malpractice claims, or ensure that legal standards of care were met. The extent to which concerns about medical malpractice influence assurance behaviors of pathologists interpreting breast specimens is unknown. Methods: Breast pathologists (n = 252) enrolled in a nationwide study completed an online survey of attitudes regarding malpractice and perceived alterations in interpretive behavior due to concerns of malpractice. Associations between pathologist characteristics and the impact of malpractice concerns on personal and colleagues' assurance behaviors were determined by χ2 and logistic regression analysis. Results: Most participants reported using one or more assurance behaviors due to concerns about medical malpractice for both their personal (88%) and colleagues' (88%) practices, including ordering additional stains, recommending additional surgical sampling, obtaining second reviews, or choosing the more severe diagnosis for borderline cases. Nervousness over breast pathology was positively associated with assurance behavior and remained statistically significant in a multivariable logistic regression model (odds ratio, 2.5; 95% confidence interval, 1.0-6.1; P =.043). Conclusions: Practicing US breast pathologists report exercising defensive medicine by using assurance behaviors due to malpractice concerns.
    Preview · Article · Dec 2015 · American Journal of Clinical Pathology
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    ABSTRACT: Background Elevated mammographic density (MD) is a strong breast cancer risk factor but the mechanisms underlying the association are poorly understood. High MD and breast cancer risk may reflect cumulative exposures to factors that promote epithelial cell division. One marker of cellular replicative history is telomere length, but its association with MD is unknown. We investigated the relation of telomere length, a marker of cellular replicative history, with MD and biopsy diagnosis. Methods One hundred and ninety-five women, ages 40–65, were clinically referred for image-guided breast biopsies at an academic facility in Vermont. Relative peripheral blood leukocyte telomere length (LTL) was measured using quantitative polymerase chain reaction. MD volume was quantified in cranio-caudal views of the breast contralateral to the primary diagnosis in digital mammograms using a breast density phantom, while MD area (cm2) was measured using thresholding software. Associations between log-transformed LTL and continuous MD measurements (volume and area) were evaluated using linear regression models adjusted for age and body mass index. Analyses were stratified by biopsy diagnosis: proliferative (hyperplasia, in-situ or invasive carcinoma) or non-proliferative (benign or other non-proliferative benign diagnoses). Results Mean relative LTL in women with proliferative disease (n = 141) was 1.6 (SD = 0.9) vs. 1.2 (SD = 0.6) in those with non-proliferative diagnoses (n = 54) (P = 0.002). Mean percent MD volume did not differ by diagnosis (P = 0.69). LTL was not associated with MD in women with proliferative (P = 0.89) or non-proliferative (P = 0.48) diagnoses. However, LTL was associated with a significant increased risk of proliferative diagnosis (adjusted OR = 2.46, 95 % CI: 1.47, 4.42). Conclusions Our analysis of LTL did not find an association with MD. However, our findings suggest that LTL may be a marker of risk for proliferative pathology among women referred for biopsy based on breast imaging.
    Preview · Article · Dec 2015 · BMC Cancer
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    ABSTRACT: Long non-coding RNAs (lncRNAs) are potential biomarkers for breast cancer risk stratification. LncRNA expression has been investigated primarily by RNA sequencing, quantitative reverse transcription PCR or microarray techniques. In this study, six breast cancer-implicated lncRNAs were investigated by chromogenic in situ hybridisation (CISH). Invasive breast carcinoma (IBC), ductal carcinoma in situ (DCIS) and normal adjacent (NA) breast tissues from 52 patients were screened by CISH. Staining was graded by modified Allred scoring. HOTAIR, H19 and KCNQ1OT1 had significantly higher expression levels in IBC and DCIS than NA (p<0.05), and HOTAIR and H19 were expressed more strongly in IBC than in DCIS tissues (p<0.05). HOTAIR and KCNQ101T were expressed in tumour cells; H19 and MEG3 were expressed in stromal microenvironment cells; MALAT1 was expressed in all cells strongly and ZFAS1 was negative or weakly expressed in all specimens. These data corroborate the involvement of three lncRNAs (HOTAIR, H19 and KCNQ1OT1) in breast tumourigenesis and support lncRNA CISH as a potential clinical assay. Importantly, CISH allows identification of the tissue compartment expressing lncRNA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
    No preview · Article · Aug 2015 · Journal of clinical pathology

  • No preview · Article · Aug 2015 · Cancer Research
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    ABSTRACT: Margin status is important in guiding decisions to re-excise following breast-conserving surgery (BCS) for breast cancer. The College of American Pathologists (CAP) developed guidelines to standardize pathology reporting; however, compliance with margin documentation guidelines has been shown to vary. The aim of this retrospective study was to determine whether compliance with CAP guidelines affects re-excision and mastectomy rates. We identified 1423 patients diagnosed with breast cancer between 1998 and 2006 who underwent BCS with negative margins. CAP compliance was categorized as maximal, minimal, or non-compliant. Statistical analyses were performed comparing the frequency of re-excision and mastectomy after initial BCS according to CAP margin reporting guideline compliance. Data were adjusted for provider facility by including a clustering variable within the regression model. Patients with non-compliant margin reporting were 1.7 times more likely to undergo re-excision and/or mastectomy than those with maximally compliant reporting. Level of compliance was most strongly associated with the frequency of mastectomy; non-compliant margin reporting was associated with a 2.5-fold increase in mastectomy rates compared to maximally compliant reporting. The results did not substantially change when the analyses accounted for clustering at the provider facility level. Our findings suggest that compliance with CAP guidelines in pathology reporting may be associated with variation in re-excision and mastectomy rates following BCS. Copyright © 2015 Elsevier Ltd. All rights reserved.
    No preview · Article · Jul 2015 · Breast (Edinburgh, Scotland)
  • Joann G Elmore · Margaret S Pepe · Donald L Weaver

    No preview · Article · Jul 2015 · JAMA The Journal of the American Medical Association
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    ABSTRACT: General frameworks of the cancer screening process are available, but none directly compare the process in detail across different organ sites. This limits the ability of medical and public health professionals to develop and evaluate coordinated screening programs that apply resources and population management strategies available for one cancer site to other sites. We present a trans-organ conceptual model that incorporates a single screening episode for breast, cervical, and colorectal cancers into a unified framework based on clinical guidelines and protocols; the model concepts could be expanded to other organ sites. The model covers four types of care in the screening process: risk assessment, detection, diagnosis, and treatment. Interfaces between different provider teams (eg, primary care and specialty care), including communication and transfer of responsibility, may occur when transitioning between types of care. Our model highlights across each organ site similarities and differences in steps, interfaces, and transitions in the screening process and documents the conclusion of a screening episode. This model was developed within the National Cancer Institute-funded consortium Population-based Research Optimizing Screening through Personalized Regimens (PROSPR). PROSPR aims to optimize the screening process for breast, cervical, and colorectal cancer and includes seven research centers and a statistical coordinating center. Given current health care reform initiatives in the United States, this conceptual model can facilitate the development of comprehensive quality metrics for cancer screening and promote trans-organ comparative cancer screening research. PROSPR findings will support the design of interventions that improve screening outcomes across multiple cancer sites. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
    No preview · Article · Jun 2015 · Journal of the National Cancer Institute
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    ABSTRACT: A breast pathology diagnosis provides the basis for clinical treatment and management decisions; however, its accuracy is inadequately understood. To quantify the magnitude of diagnostic disagreement among pathologists compared with a consensus panel reference diagnosis and to evaluate associated patient and pathologist characteristics. Study of pathologists who interpret breast biopsies in clinical practices in 8 US states. Participants independently interpreted slides between November 2011 and May 2014 from test sets of 60 breast biopsies (240 total cases, 1 slide per case), including 23 cases of invasive breast cancer, 73 ductal carcinoma in situ (DCIS), 72 with atypical hyperplasia (atypia), and 72 benign cases without atypia. Participants were blinded to the interpretations of other study pathologists and consensus panel members. Among the 3 consensus panel members, unanimous agreement of their independent diagnoses was 75%, and concordance with the consensus-derived reference diagnoses was 90.3%. The proportions of diagnoses overinterpreted and underinterpreted relative to the consensus-derived reference diagnoses were assessed. Sixty-five percent of invited, responding pathologists were eligible and consented to participate. Of these, 91% (N = 115) completed the study, providing 6900 individual case diagnoses. Compared with the consensus-derived reference diagnosis, the overall concordance rate of diagnostic interpretations of participating pathologists was 75.3% (95% CI, 73.4%-77.0%; 5194 of 6900 interpretations). Among invasive carcinoma cases (663 interpretations), 96% (95% CI, 94%-97%) were concordant, and 4% (95% CI, 3%-6%) were underinterpreted; among DCIS cases (2097 interpretations), 84% (95% CI, 82%-86%) were concordant, 3% (95% CI, 2%-4%) were overinterpreted, and 13% (95% CI, 12%-15%) were underinterpreted; among atypia cases (2070 interpretations), 48% (95% CI, 44%-52%) were concordant, 17% (95% CI, 15%-21%) were overinterpreted, and 35% (95% CI, 31%-39%) were underinterpreted; and among benign cases without atypia (2070 interpretations), 87% (95% CI, 85%-89%) were concordant and 13% (95% CI, 11%-15%) were overinterpreted. Disagreement with the reference diagnosis was statistically significantly higher among biopsies from women with higher (n = 122) vs lower (n = 118) breast density on prior mammograms (overall concordance rate, 73% [95% CI, 71%-75%] for higher vs 77% [95% CI, 75%-80%] for lower, P < .001), and among pathologists who interpreted lower weekly case volumes (P < .001) or worked in smaller practices (P = .034) or nonacademic settings (P = .007). In this study of pathologists, in which diagnostic interpretation was based on a single breast biopsy slide, overall agreement between the individual pathologists' interpretations and the expert consensus-derived reference diagnoses was 75.3%, with the highest level of concordance for invasive carcinoma and lower levels of concordance for DCIS and atypia. Further research is needed to understand the relationship of these findings with patient management.
    No preview · Article · Mar 2015 · JAMA The Journal of the American Medical Association
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    ABSTRACT: Elevated mammographic density is a breast cancer risk factor, which has a suggestive, but unproven, relationship with increased exposure to sex steroid hormones. We examined associations of serum estrogens and estrogen metabolites with area and novel volume mammographic density measures among 187 women, ages 40–65, undergoing diagnostic breast biopsies at an academic facility in Vermont. Serum parent estrogens, estrone and estradiol, and their 2-, 4-, and 16-hydroxylated metabolites were measured using liquid chromatography-tandem mass spectrometry. Area mammographic density was measured in the breast contralateral to the biopsy using thresholding software; volume mammographic density was quantified using a density phantom. Linear regression was used to estimate associations of estrogens with mammographic densities, adjusted for age and body mass index, and stratified by menopausal status and menstrual cycle phase. Weak, positive associations between estrogens, estrogen metabolites, and mammographic density were observed, primarily among postmenopausal women. Among premenopausal luteal phase women, the 16-pathway metabolite estriol was associated with percent area (p = 0.04) and volume (p = 0.05) mammographic densities and absolute area (p = 0.02) and volume (p = 0.05) densities. Among postmenopausal women, levels of total estrogens, the sum of parent estrogens, and 2-, 4- and 16-hydroxylation pathway metabolites were positively associated with area density measures (percent: p = 0.03, p = 0.04, p = 0.01, p = 0.02, p = 0.07; absolute: p = 0.02, p = 0.02, p = 0.01, p = 0.02, p = 0.03, respectively) but not volume density measures. Our data suggest that serum estrogen profiles are weak determinants of mammographic density and that analysis of different density metrics may provide complementary information about relationships of estrogen exposure to breast tissue composition.
    No preview · Article · Mar 2015
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    ABSTRACT: BACKGROUND Current data on the pathologic diagnoses of breast biopsy after mammography can inform patients, clinicians, and researchers about important population trends.METHODS Breast Cancer Surveillance Consortium data on 4,020,140 mammograms between 1996 and 2008 were linked to 76,567 pathology specimens. Trends in diagnoses in biopsies by time and risk factors (patient age, breast density, and family history of breast cancer) were examined for screening and diagnostic mammography (performed for a breast symptom or short-interval follow-up).RESULTSOf the total mammograms, 88.5% were screening and 11.5% diagnostic; 1.2% of screening and 6.8% of diagnostic mammograms were followed by biopsies. The frequency of biopsies over time was stable after screening mammograms, but increased after diagnostic mammograms. For biopsies obtained after screening, frequencies of invasive carcinoma increased over time for women ages 40-49 and 60-69, Ductal carcinoma in situ (DCIS) increased for those ages 40-69, whereas benign diagnoses decreased for all ages. No trends in pathology diagnoses were found following diagnostic mammograms. Dense breast tissue was associated with high-risk lesions and DCIS relative to nondense breast tissue. Family history of breast cancer was associated with DCIS and invasive cancer.CONCLUSIONS Although the frequency of breast biopsy after screening mammography has not changed over time, the percentages of biopsies with DCIS and invasive cancer diagnoses have increased. Among biopsies following mammography, women with dense breasts or family history of breast cancer were more likely to have high-risk lesions or invasive cancer. These findings are relevant to breast cancer screening and diagnostic practices. Cancer 2015. © 2015 American Cancer Society.
    No preview · Article · Jan 2015 · Cancer

  • No preview · Article · Jan 2015 · Journal of Investigative Medicine
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    ABSTRACT: Physician attributes, job satisfaction and confidence in clinical skills are associated with enhanced performance and better patient outcomes. We surveyed 252 pathologists to evaluate associations between enjoyment of breast pathology, demographic/clinical characteristics and diagnostic performance. Diagnostic performance was determined by comparing pathologist assessments of a set of 60 cases with consensus assessments of the same cases made by a panel of experienced pathologists. Eighty-three percent of study participants reported enjoying breast pathology. Pathologists who enjoy breast interpretation were more likely to review ≥10 cases/week (p = 0.003), report breast interpretation expertise (p = 0.013) and have high levels of confidence interpreting breast pathology (p < 0.001). These pathologists were less likely to report that the field was challenging (p < 0.001) and that breast cases make them more nervous than other types of pathology (p < 0.001). Enjoyment was not associated with diagnostic performance. Millions of women undergo breast biopsy annually, thus it is reassuring that although nearly a fifth of practicing pathologists who interpret breast tissue report not enjoying the field, precision is not impacted. Copyright © 2014 Elsevier Ltd. All rights reserved.
    No preview · Article · Dec 2014 · Breast (Edinburgh, Scotland)
  • E. Mercan · S. Aksoy · L.G. Shapiro · D.L. Weaver · T. Brunye · J.G. Elmore
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    ABSTRACT: Whole slide imaging technology enables pathologists to screen biopsy images and make a diagnosis in a digital form. This creates an opportunity to understand the screening patterns of expert pathologists and extract the patterns that lead to accurate and efficient diagnoses. For this purpose, we are taking the first step to interpret the recorded actions of world-class expert pathologists on a set of digitized breast biopsy images. We propose an algorithm to extract regions of interest from the logs of image screenings using zoom levels, time and the magnitude of panning motion. Using diagnostically relevant regions marked by experts, we use the visual bag-of-words model with texture and color features to describe these regions and train probabilistic classifiers to predict similar regions of interest in new whole slide images. The proposed algorithm gives promising results for detecting diagnostically relevant regions. We hope this attempt to predict the regions that attract pathologists' attention will provide the first step in a more comprehensive study to understand the diagnostic patterns in histopathology.
    No preview · Article · Dec 2014

  • No preview · Article · Oct 2014 · Cancer Research
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    ABSTRACT: Breast cancer screening holds a prominent place in public health, health care delivery, policy, and women's health care decisions. Several factors are driving shifts in how population-based breast cancer screening is approached, including advanced imaging technologies, health system performance measures, health care reform, concern for “overdiagnosis,” and improved understanding of risk. Maximizing benefits while minimizing the harms of screening requires moving from a “1-size-fits-all” guideline paradigm to more personalized strategies. A refined conceptual model for breast cancer screening is needed to align women's risks and preferences with screening regimens. A conceptual model of personalized breast cancer screening is presented herein that emphasizes key domains and transitions throughout the screening process, as well as multilevel perspectives. The key domains of screening awareness, detection, diagnosis, and treatment and survivorship are conceptualized to function at the level of the patient, provider, facility, health care system, and population/policy arena. Personalized breast cancer screening can be assessed across these domains with both process and outcome measures. Identifying, evaluating, and monitoring process measures in screening is a focus of a National Cancer Institute initiative entitled PROSPR (Population-based Research Optimizing Screening through Personalized Regimens), which will provide generalizable evidence for a risk-based model of breast cancer screening, The model presented builds on prior breast cancer screening models and may serve to identify new measures to optimize benefits-to-harms tradeoffs in population-based screening, which is a timely goal in the era of health care reform. Cancer 2014. © 2014 American Cancer Society.
    Full-text · Article · Oct 2014 · Cancer
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    Full-text · Article · Sep 2014 · Journal of Clinical Oncology
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    ABSTRACT: Background: Mammographic density (MD), the area of non-fatty appearing tissue divided by total breast area, is a strong breast cancer risk factor. Most MD analyses have employed visual categorizations or computer-assisted quantification, which ignore breast thickness. We explored MD volume and area, using a volumetric approach previously validated as predictive of breast cancer risk, in relation to risk factors among women undergoing breast biopsy. Methods: Among 413 primarily white women, ages 40-65, undergoing diagnostic breast biopsies between 2007-2010 at an academic facility in Vermont, MD volume (cm3) was quantified in cranio-caudal views of the breast contralateral to the biopsy target using a density phantom, while MD area (cm2) was measured on the same digital mammograms using thresholding software. Risk factor associations with continuous MD measurements were evaluated using linear regression. Results: Percent MD volume and area were correlated (r=0.81) and strongly and inversely associated with age, body mass index (BMI), and menopause. Both measures were inversely associated with smoking and positively associated with breast biopsy history. Absolute MD measures were correlated (r=0.46) and inversely related to age and menopause. Whereas absolute dense area was inversely associated with BMI, absolute dense volume was positively associated. Conclusions: Volume and area MD measures exhibit some overlap in risk factor associations, but divergence as well, particularly for BMI. Impact: Findings suggest that volume and area density measures differ in subsets of women; notably, among obese women, absolute density was higher with volumetric methods, suggesting that breast cancer risk assessments may vary for these techniques.
    No preview · Article · Aug 2014 · Cancer Epidemiology Biomarkers & Prevention
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    ABSTRACT: A pilot study examined the extent to which eye movements occurring during interpretation of digitized breast biopsy whole slide images (WSI) can distinguish novice interpreters from experts, informing assessments of competency progression during training and across the physician-learning continuum. A pathologist with fellowship training in breast pathology interpreted digital WSI of breast tissue and marked the region of highest diagnostic relevance (dROI). These same images were then evaluated using computer vision techniques to identify visually salient regions of interest (vROI) without diagnostic relevance. A non-invasive eye tracking system recorded pathologists' (N = 7) visual behavior during image interpretation, and we measured differential viewing of vROIs versus dROIs according to their level of expertise. Pathologists with relatively low expertise in interpreting breast pathology were more likely to fixate on, and subsequently return to, diagnostically irrelevant vROIs relative to experts. Repeatedly fixating on the distracting vROI showed limited value in predicting diagnostic failure. These preliminary results suggest that eye movements occurring during digital slide interpretation can characterize expertise development by demonstrating differential attraction to diagnostically relevant versus visually distracting image regions. These results carry both theoretical implications and potential for monitoring and evaluating student progress and providing automated feedback and scanning guidance in educational settings.
    Full-text · Article · Aug 2014 · PLoS ONE

Publication Stats

11k Citations
929.00 Total Impact Points

Institutions

  • 1993-2015
    • University of Vermont
      • • Department of Pathology
      • • College of Medicine
      • • Department of Surgery
      Burlington, Vermont, United States
  • 2014
    • University of Pittsburgh
      Pittsburgh, Pennsylvania, United States
  • 2002-2013
    • University of California, San Francisco
      • • Division of General Internal Medicine
      • • Division of Hospital Medicine
      San Francisco, California, United States
  • 2012
    • Tufts University
      • Department of Psychology
      Бостон, Georgia, United States
  • 1995-2010
    • University of Vermont Medical Center
      Burlington, Vermont, United States
  • 1998-2009
    • Fletcher Allen Health Care
      Burlington, Vermont, United States